8 - Congenital Defects

Question 1

What does congenital mean?

Answer 1

Present at birth

Question 2

How many percent of live births have some sort of defect?

Answer 2

20%

Question 3

How many percent of birth defects are due to unknown causes/multi-factorial?

Answer 3

70%

Question 4

How many percent of birth defects are due to genetics?

Answer 4

15% e.g downs syndrome

Question 5

How many percent of birth defects are due to drugs?

Answer 5

10% e.g accutane and thalidomide

Question 6

How many percent of birth defects are due to environmental factors?

Answer 6

10% e.g infectious and chemical agents - rubella - CMV - zika - alcohol

Question 7

What is a major congenital defect and how many percent of births are major?

Answer 7

Anomaly that requires surgical treatment
Causes significant handicap
6%

Question 8

What is a minor congenital defect and how many percent of births are minor?

Answer 8

Anomaly that doesn’t require intervention
Causes minimal handicap
15%

Question 9

What is cryptochidism and what is its incidence?

Answer 9

Undecended testis
7.6:1000 births
1-4% of live male births
most correct within 3 months
1% still undescended at 1 year

Question 10

Name 5 major congenital defects?

Answer 10

• Anecephaly
• Cleft lip and cleft palate
• Spina bifida
• Hyposapadias
• Phocomelia

Question 11

Name 5 minor congenital defects?

Answer 11

Micropenis
Cryptorchidism
Auricular ear tag or pit
Rocker bottom feet
Overlapping digits

Question 12

Anecephaly

Answer 12

failure of anterior neuropore to close resulting in malformed head and brain

Question 13

Spina bifida

Answer 13

failure of posterior neuropore to close leading to the spine and its contents herniating out the back of the child

Question 14

Hypospadias

Answer 14

defect in the formation of the male urethra where it opens out an unusual place – classified as a major defect but is rarely life threatening

Question 15

Cleft lip

Answer 15

failure of maxillary and medial nasal prominences to fuse

Question 16

Cleft palate

Answer 16

failure of palatine shelves to fuse

Question 17

Holoprosencepahly

Answer 17

loss of midline structures – severity can vary

Question 18

Omphalocele

Answer 18

where the abdominal contents do not correctly return to the body from the umbilical cord

Question 19

Gastrochisis

Answer 19

defect in the anterior abdominal wall through which the abdominal contents herniate

Question 20

Phocomelia

Answer 20

malformation of the limbs – thalidomide

Question 21

Talipes equimovarus

Answer 21

club foot where foot is rotated internally at the ankle

Question 22

Cryptorchidism

Answer 22

undescended testicles – minor – 7.6:1000 – 1-4% of births – most spontaneously correct within 3 months. Still undescended in 1% at 1 year of age – 20X increased risk of developing malignancy

Question 23

Syndactyly

Answer 23

digits fused together

Question 24

Polydactyly

Answer 24

extra digits

Question 25

Ankyloglossia

Answer 25

tongue tie – unusually short and thickened frenulum

Question 26

Congenital diaphragmatic hernia

Answer 26

some of the gut herniates into the thorax through the oesophageal hiatus preventing correct development of the lungs and leaving the baby cyanotic

Question 27

Hydatidiform mole

Answer 27

cell diploid but all derived from the father due to fertilisation of an empty egg

Question 28

Sirenomelia

Answer 28

epiblast cells stop invaginating too early meaning insufficient mesoderm is produced and the lower body parts are fused together

Question 29

Situs invertus

Answer 29

left and right body axes are the opposite way around

Question 30

Atrial septal defect

Answer 30

blood can flow between two atria

Question 31

Ventricular septal defect

Answer 31

blood can flow between two ventricles

Question 32

AV canal

Answer 32

lack of atrioventricular septum

Question 33

Patent ductus arteriosus

Answer 33

failure of ductus arteriosus to close

Question 34

Coarctation of aorta

Answer 34

aortic narrowing around where the ductus arteriosus inserts

Question 35

Transposition of the great vessels

Answer 35

incorrect connection of outflow tracts to the chambers

Question 36

Truncus arteriosus

Answer 36

failure of truncus arteriosus to properly divide into the aorta and pulmonary trunk

Question 37

Tetralogy of Fallot

Answer 37

overriding aorta that can also break through to the wrong side of the heart

Question 38

Pelvic kidney

Answer 38

kidneys do not migrate upwards to the posterior abdominal wall

Question 39

Horseshoe kidney

Answer 39

kidneys fuse at the bottom to form a horseshoe shape

Question 40

Vitelline duct abnormality

Answer 40

Meckel’s diverticulum - small pocket of remaining vitelline duct outpocketing from the ileum

Question 41

Oesophgeal atresia

Answer 41

chronic narrowing of the oesophagus

Question 42

Tracheo-oesophageal fistulae

Answer 42

abnormal connection between the trachea and oesophagus

Question 43

Pyloric stenosis

Answer 43

narrowing of the pylorus leading from the stomach to duodenum

Question 44

Duodenal atresia

Answer 44

closure of the lumen of the duodenum

Question 45

Jejunal atresia

Answer 45

closure of the lumen of the jejunum

Question 46

Malrotation

Answer 46

improper rotation of the midgut that can lead to volvulus (strangulation) and obstruction • Imperforate anus – malformation of the rectum

Question 47

Imperforate anus

Answer 47

malformation of the rectum

Question 48

Hirschprung’s disease

Answer 48

lack of ganglion cells to the intestines meaning they cannot function correctly

Question 49

What occurs during week one after fertilisation?

Answer 49

- Fertilisation in ampulla region of uterine tube within 24 hours of ovulation - 3 days after fertilization – ball of cells – morula

Question 50

What occurs in week 2 after fertilisation?

Answer 50

Trophoblast, embryoblast differentiates into two layers | 2 cavities are formed

Question 51

What are the names of the 2 layers the trophoblast differentiates into?

Answer 51

Syncytioblast and cytotrophoblast

Question 52

What are the names of the 2 layers the embryoblast differentiates into?

Answer 52

Epiblast dorsally and hypoblast ventrally

Question 53

What are the names of the two cavities formed?

Answer 53

Amniotic cavity dorsal to epiblast and yolk sac cavity ventral to hypoblast

Question 54

What occurs during week three after fertilisation?

Answer 54

o Two layers transformed by gastrulation into three germ layers o Ectoderm – mesoderm – endoderm o Establishes body axes – cranial/caudal – dorsal/ventral – left/right